glorious DDA

#ifndef clFreeStep_h__
#define clFreeStep_h__

#include "clVector3.h"

class clFreeStep3
{
public:
  clFreeStep3(const clVec3 &pos, const clVec3 &dir)
  {
    m_pos = v3I(clFloor(pos));
    v3 invDir = v3(1.0) / clAbs(dir);
    const i32 quality = 32;
    invDir = clMin(invDir, v3(f32(clMaxValue<i32>() / quality)));
    invDir *= (clMaxValue<i32>() / quality) / clMaxComponent(invDir);
    v3 invDirSqrRounded = v3(clRound(invDir));
    m_waveLengths = v3I(invDirSqrRounded);
    clVec3I m_iSign = v3I(dir.x >= 0, dir.y >= 0, dir.z >= 0);
    m_sign = m_iSign * 2 - 1;
    v3 crossDist = (v3(m_pos + m_iSign) - pos);
    m_wavePhase = v3I(clAbs(crossDist) * m_waveLengths);
    auto d((v3(1.0) / m_waveLengths).Normalized()[0] * m_waveLengths[0]);
    m_pipsPerMeter = i32(d);
  }

  clVec3I Step()
  {
    ui8 minIndex = clMinComponentIndex(m_wavePhase);
    i32 sub = m_wavePhase[minIndex];
    m_wavePhase -= sub;
    m_wavePhase[minIndex] = m_waveLengths[minIndex];
    m_pos[minIndex] += m_sign[minIndex];
    return m_pos;
  }

  void Jump(i32 distance)
  {
    v3I64 pipDistance = v3I64(i64(m_pipsPerMeter) * distance);
    v3I64 wholeSteps = pipDistance / m_waveLengths;
    pipDistance -= wholeSteps * m_waveLengths;
    v3I64 additionalWholeSteps = (pipDistance + m_waveLengths - m_wavePhase) / m_waveLengths;
    wholeSteps += additionalWholeSteps;
    v3I64 newPips = m_wavePhase - pipDistance + m_waveLengths;
    for (int i = 0; i < 3; i++) m_wavePhase[i] = i32(newPips[i] % m_waveLengths[i]);
    m_pos += v3I(wholeSteps * m_sign);
  }

public:
  clVec3I m_pos;
  clVec3I m_sign;
  v3I m_wavePhase;
  v3I m_waveLengths;
  i32 m_pipsPerMeter;
};

#endif // clFreeStep_h__